The Research Of A Newtype Surface Modified Polyethylene Terepthalate(PET) Artificial Ligament

Anterior Cruciate Ligament Reconstruction with LARS (Ligament Advanced Reinforcement System) Artificial Ligament With5-to7-Year Follow-upPurpose:This study aims to clinical follow-up LARS artificial ligament reconstruction of anterior cruciate ligament reconstruction with5～7years postoperatively.Methods:Twenty-one participants with ACL reconstruction were recruited in this study, all of them used LARS artificial ligaments. All of them had unilateral ACL reconstruction, and were followed up using3.0-T MRI scan at5～7years after operation. Clinical examination was performed at the same day when the MRI examination was performed, including subjective functional examinations (International Knee Documentation Committee (IKDC) score, Tegner Lysholm Knee Scoring (TLKS) Scale) and physical examinations (anterior drawer test (ADT) and Lachman test). MRI images were used to analyze the morphology of the grafts.Results:17participants acquired full functional strength and stability, and MRI findings revealed that the graft was curved. The complications occurred in4patients, including knee synovitis, complete rupture and partial rupture.Conclusion:ACL reconstruction with LARS artificial ligament used in patients has a very good outcome at mean of5～7years follow-up. The overall complications indicated the artificial ligament has a poor ligamentization after implantation. (1) Hydroxyapatite Coating Enhance Polyethylene Terepthalate Artificial Ligament Graft Osteointegration in bone tunnelPurpose:The purpose of this study was to investigate whether hydroxyapatite (HAp) coating could induce polyethylene terepthalate (PET) artificial ligament graft osteointegration in the bone tunnel.Methods:Twenty-four New Zealand white rabbits underwent artificial ligament graft transplantation in bilateral proximal tibia tunnels. One limb was implanted with HAp coated PET graft, and the contralateral limb was implanted with non-HAp coated PET graft as control. The rabbits were randomly sacrificed at4and8weeks after surgery.Results:The load-to-failure of the experimental group at8weeks were significantly higher than those of the control group (p=0.0057) Histologically, application of HAp coating induced new bone formation between graft and bone at8weeks compared with the controls. Real time-polymerase chain reaction examination revealed significantly elevated messenger ribonucleic acid expression levels of osteopontin and collagen-I in the grafts of HAp group compared with the controls at4weeks (p<0.05)Conclusion:The study has shown that HAp coating on the PET artificial ligament surface has a positive effect in the induction of artificial ligament osteointegration within the bone tunnel. (2) Enhancement of the Osseointegration of a Poly (Ethylene Terephthalate) Artificial Ligament Graft in a Bone Tunnel using58S BioglassPurpose:To investigate whether a bioactive glass (BG) coating on the PET artificial ligament could enhance graft osseointegration by promoting bone regeneration at the interface between PET graft and bone tunnel.Methods:Thirty New Zealand white rabbits underwent artificial ligament graft transplantation in their bilateral proximal tibia tunnels. One limb was implanted with a58S BG-coated PET graft, and the contralateral limb was implanted with a non-BG coated PET graft, as a control. The rabbits were randomly sacrificed at3,6, and12weeks after surgery for biomechanical and histological examinations.Results:The maximal load-to-failure of the BG-coated experimental group were significantly higher than those of the control group at12weeks (p=0.0051). Historically, at12weeks, the BG-coated PET graft induced great new bone formation between graft and host bone, and the average graft-bone interface width of the BG group became significantly lower than that of the control group. Furthermore, the BG coating on the ligament graft surface also stimulated greater expression of bone morphogenic protein-2(BMP-2) and vascular endothelial growth factor (VEGF) around the graft in vivo compared to the control group at3weeks (p<0.05)Conclusions:This study has shown that a BG coating on the PET artificial ligament surface has a positive effect in the induction of artificial ligament osseointegration within the bone tunnel. (3) Composite coating of58S Bioglass and Hydroxyapatite on a Poly (ethylene Terepthalate) Artificial Ligament Graft for the graft osseointegration in a Bone TunnelPurpose:The purpose of this study was to determine the effect of the combination of hydroxyapatite (HAp) and bioglass (BG) on polyethylene terephthalate (PET) artificial ligament graft osseointegration within the bone tunnel.Methods:Surface modification with a compound coating of HAp-BG on the PET artificial ligament was designed for the promotion and enhancement of graft-to-bone healing after artificial ligament implantation in bone tunnel. The samples were investigated in vitro using MC3T3-E1mouse osteoblastic cells. Furthermore, a rabbit extraarticular tendon-to-bone healing model was used to evaluate the effect of this kind of surface-modified stainless artificial ligament in vivo, including biomechanical and histological examinations.Results:The results of in vitro culturing of MC3T3-E1mouse osteoblastic cells proved that this HA/BG composite coating can promote the cell compatibility of grafts. The final in vivo results demonstrated that HA/BG coating improved new bone formation at the graft-bone interface and increased the load-to-failure property of graft in bone tunnel compared to the control group at early time.Conclusion:The study has shown that HA/BG composite coating on the PET artificial ligament surface has a positive effect in the induction of artificial ligament osseointegration within the bone tunnel. (4) The Effect of a Layer-by-layer Chitosan-Hyaluronic acid Coating on Graft-to-Bone Healing of a Polyethylene Terephthalate Artificial Ligament Purpose:to investigate whether layer-by-layer self-assembled coating of chitosan and hyaluronic acid (CS-HA) could induce polyethylene terepthalate (PET) artificial ligament graft osteointegration in the bone tunnel.Methods:Surface coating with an organic layer-by-layer self-assembled template of CS-HA on a polyethylene terephthalate (PET) artificial ligament was designed for the promotion and enhancement of graft-to-bone healing after artificial ligament implantation in bone tunnel. The samples were investigated in vitro using MC3T3-E1mouse osteoblastic cells. Furthermore, a rabbit extraarticular tendon-to-bone healing model was used to evaluate the effect of this kind of surface-modified stainless artificial ligament in vivo, including biomechanical and histological examinations.Results:The results of in vitro culturing of MC3T3-E1mouse osteoblastic cells supported the hypothesis that the layer-by-layer coating of chitosan and hyaluronic acid could promote the cell compatibility of grafts and could promote osteoblast proliferation. The final results proved that this organic compound coating could significantly promote and enhance new bone formation at graft-bone interface histologically, and correspondingly, the experimental group with coating had significantly higher biomechanical property compared with controls at8weeks (P<0.05).Conclusion:The study has shown that the CS-HA coating on the PET artificial ligament surface has a positive effect in the induction of artificial ligament osteointegration within the bone tunnel. PART Three(1) The use of a layer-by-layer hyaluronic acid-chitosan coating to promote the biocompatibility of a poly (ethylene terephthalate) artificial ligament:A rabbit medial collateral ligament (MCL) reconstruction modelPurpose:To investigate whether a hyaluronic acid-chitosan coating on the PET artificial ligament could have favorable biocompatibility to facilitate cell adhesion, proliferation and collagen regeneration.Methods:In this present study, surface modification was performed on a poly (ethylene terephthalate)(PET) artificial ligament graft by layer-by-layer (LBL) self assembly coating of hyaluronic acid (HA) and chitosan (CS). The surface characterization of the ligament was examined using scanning electron microscopy (SEM), atomic force microscopy (AFM), and energy-dispersive X-ray spectroscopy (EDX). The results of in vitro culturing of human foreskin fibroblast cells (HDFCs) supported the hypothesis that the LBL coating of CS-HA could promote the cell proliferation and adhesion on the sheets. A rabbit medial collateral ligament (MCL) reconstruction model was used to evaluate the effect of this LBL coating in vivo.Results:The results of in vitro culturing of HDFCs proved that this HA/BG composite coating can promote the cell compatibility of grafts. The final in vivo results proved that this LBL coating could significantly promote and enhance new collagen formation among the graft fibers.Conclusion:On the basis of these results, we conclude that such CS-HA assembly coating could enhance PET graft biocompatibility in vitro and in vivo, and a CS-HA coated PET graft has considerable potential as a desirable substitute for ligament reconstruction. (2) The use of layer-by-layer self assembly coating of hyaluronic acid and cationized gelatin to improve biocompatibility of a poly (ethylene terephthalate) artificial ligament in the reconstruction of anterior cruciate ligamentPurpose:To investigate whether a hyaluronic acid-cationized gelatin coating on the PET artificial ligament could have favorable biocompatibility to facilitate cell adhesion, proliferation and collagen regeneration.Methods:In this present study, surface modification of polyethylene terephthalate (PET) artificial ligament graft was performed by layer-by-layer (LBL) self assembly coating of hyaluronic acid (HA) and cationized gelatin (CG). The change of surface property was compared by contact angles, energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) measurement. The results of in vitro culturing of human foreskin fibroblast cells (HDFCs) supported the hypothesis that the LBL coating of CS-HA could promote the cell proliferation and adhesion on the sheets. Rabbit and porcine anterior cruciate ligament (ACL) reconstruction models were used to evaluate the effect of this LBL coating in vivo.Results:The results of in vitro studies demonstrated that the CG-HA coating PET graft showed significantly enhanced cell adhesion, cell proliferation and matrix production compared with the pure PET graft. Additionally, the expression of collagen on the CG-HA coating group was much higher than that of the control group. The final results proved that this CG-HA coating could significantly promote and enhance new collagen formation among the graft fibers.Conclusion:On the basis of these results, we conclude that such CG-HA assembly coating enhanced PET graft biocompatibility in vitro, and a CG-HA coated PET graft has considerable potential as a desirable substitute for ligament reconstruction. PART Ⅳ New design of artificial ligamentIn order to overcome the existing defects of LARS ligament, we provide a kind of artificial ligament, which can connect with a button to increase graft biomechanical property, and can better promote the graft-bone contact thus to strengthen the graft-bone healing. This has been applied as chinese patent.